I expected that when I spawned a baby horse in and gave it an apple, it would grow to a mature horse and I would be able to ride it.
That was not the case. Once I gave it an apple, it would not let me get on it, and it turned my head by some unknown degree.

Steps to Reproduce:
1. Spawn a horse with a spawn egg.
2. If it is not a baby, use the spawn egg on the mature horse.
3. Use an apple on the baby horse.
4. Try to ride/tame it.